Ice Age Floods National Geologic Trail • WA,OR,ID,MT

Green Monarch Ridge by Lake Pend Oreille ID

Large butte with lake in the foreground

Steamboat rock in the foreground with Banks Lake in the distance

Dry Lake lake bed and falls blanked with snow.

A overhead shot of the Dry Falls area

At the end of the last Ice Age, 18,000 to 15,000 years ago, an ice dam in northern Idaho created Glacial Lake Missoula stretching 3,000 square miles around Missoula, Montana. The dam burst and released flood waters across Washington, down the Columbia River into Oregon before reaching the Pacific Ocean. The Ice Age Floods forever changed the lives and landscape of the Pacific Northwest.

Green Monarch Ridge by Lake Pend Oreille ID
NPS Photo

Steamboat Rock State Park, Washington
NPS

Banks Lake view from Steamboat Rock
NPS

Dry Lake lake bed and falls in winter
NPS Photo

A beautiful shot from the ledge near the visitor's center in the Dry Falls area.
NPS/Cline

This animation helps viewers connect the floods complex sequence of events.

Explore the complex sequence of events through Ice Age Floods animation.

Columbia River runs through dark green hill sides illuminated by a ray of light on a cloudy day.

Learn the story of the Missoula Floods.

basalt hillside has green trees in front of it.

Explore Ice Age Floods National Geologic Trail and the 4 states which the Missoula Floods flowed through.

Last updated: January 15, 2026

Learning About Ice Age Floods

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Mailing Address:

Program Manager
Ice Age Floods National Geologic Trail
1008 Crest Drive
Coulee Dam, WA 99116

Phone:

(509) 237-9722

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